Best 20 Gallon Fish Tank Review – The Ultimate Guide

Best 20 Gallon Fish Tank

Setting up a fish tank can be daunting if you’re just getting started. But it is actually easier than you think.

Regardless of whether or not this is your first time, setting one up can be an exciting journey! In preparation for such adventures in life, there are many accessories and products available. 

At the very beginning, you’ll choose a fish tank. But what size would be suitable? I would say – why not a 20-gallon?

A twenty-gallon aquarium is your perfect size for those who want to keep tropical fish, and it will hold many species of small community tanks with ease!

A 20-gallon fish tank is a small but not too uncommon size! You can usually fit one of these at your house with room to spare. 

But, how to get the Best 20 Gallon Fish Tank? If you don’t know where to start, this post will help!

Best 20 Gallon Fish Tank: 6 Top Picks Reviewed

The Marina LED Aquarium Kit is a great way to get started with an underwater environment. With this aquarium kit, you can enjoy the beauty and complexity of aquatic life without having all those pesky chores like cleaning your tank or maintaining it on top of everything else! 

The set includes such necessities as an S20 clip-on filter to provide high-performance filtration for any fresh or saltwater setting. Plus, there are also quick-change cartridges for quick maintenance.

The Marina LED Aquarium Kit is the perfect present for any child who loves aquatic pets. It’s a great way to get kids started in fish keeping without ever having trouble with their first pet!


  • Sturdy and high-quality glass tank.
  • Very reliable.
  • Energy-efficient LEDs
  • Great as a starter kit.
  • The filter is quiet with an adjustable flow.


  • No cover for feeding cut out.
  • Doesn’t come with a heater.

It’s simple yet elegant – anyone who wants an elegant touch without having to spend too much money will love it. The Tetra 20 Gallon Glass Aquarium Kit is a complete and healthy fish tank that comes with everything you need to set up a beautiful yet straightforward aquarium. Plus, they are modern enough to fit in well with today’s homes but classic, so they’ll still look great years from now!

It includes the Tetra LED Daylight Bulb, which emits a natural daylight spectrum that enhances plant growth and coloration. The kit also consists of a Whisper Filter with adjustable flow control to keep your tank clean and clear from debris without disturbing the fish. 

This system features an easy-to-clean cartridge filter that can be removed from the housing for convenient maintenance. In addition, the kit comes with artificial plants that add a unique, natural ocean feel while giving your fish a place to hide, which reduces their stress.


  • Includes everything that is required.
  • Good quality LED lights. 
  • Includes a heater.
  • Lifetime warranty.
  • The glass is scratch-proof.


  • Strong filter output.
  • Relatively heavier.

The SeaClear 20 Gallon Hexagon Aquarium is a beautiful addition to any home or office. Its unique design gives the illusion of endless space for your viewing pleasure. This combo also includes a full spectrum LED lighting system, which provides optimal lighting for your fish and corals.

The SeaClear Acrylic Aquarium Combo Set is a product for getting into the aquarium lifestyle. Choose from black, transparent, or cobalt lights and reflectors that will add just enough light so your fish can swim around freely without being afraid of their new home!

These fish tanks are 17 times clearer than glass and can withstand even roughest handling, but they’re prone to scratches like lower-quality plastics. On the other hand, the transparent material makes it easy for you to see your beautiful tank from all angles – so you can watch all of your fish’s natural behaviors. In addition, the SeaClear 20 Gallon Acrylic Aquarium is safe for both saltwater and freshwater tanks!


  • Multiple shapes and sizes are available.
  • Include LED lighting and background reflector.
  • More impact-resistant than glass.
  • 17 times clearer than glass and shatterproof.


  • Relatively pricy.
  • Prone to scratches.

Why not start your own aquatic journey with the Aqueon Aquarium Starter Kit? This kit includes everything you need to put together a healthy and vibrant environment for fish.

Aqueon 20 Gallon Aquarium Starter Kit includes a preset heater, a filter with a red LED light that flashes to indicate when it’s time to change the cartridge, and vibrant cool white LED lighting. The low-profile hood contains the lamps and provides an unobstructed view of your aquatic environment.

Aqueon 20 Gallon Aquarium Starter Kit is one of my favorite all-in-one kits that come with an enhanced five-stage filtration system, as well as a comprehensive guidebook on how to set up and maintain it. In addition, you will get fish food for your Fishes, water conditioner, so they don’t grow algae too quickly in their new home – plus there’s even some decor included! So what do we need now? 


  • All-in-one aquarium kit.
  • Reliable and affordable.
  • Energy-efficient LED lights.
  • It comes with food and water conditioner samples.


  • Included heaters may struggle.

Get started with the perfect starter kit! You don’t have to be an expert in fish care or know much about the best tanks for them. The GloFish Aquarium Kit has everything you need and comes at a great price! 

The blue LED light completely transforms your aquarium into a colorful, neon display that is sure to impress family and friends. The GloFish Glass Aquariums are made in the USA with scratch-resistant glass and feature vibrant LED lighting that enhances the colors of fluorescent décor and GloFish. 

This kit comes complete with an easy-to-use filter system, water conditioner, test kit, food sample, netting for plants, and more!

The 20-gallon kit is perfect for any Glofish, including the Zebrafish and Tetra varieties. In addition, it can accommodate a variety of aquatic animals, so you won’t have to worry about getting stuck with only one kind!


  • Great all-in-one aquarium kit.
  • Beautiful kit.
  • The included mini heater is efficient.
  • Aesthetically pleasing light effect.


  • Filter output may be too strong.

The Tetra ColorFusion Aquarium Fish Tank Kit is the perfect choice for those looking to inject some fun into their home. This kit includes a low-profile hood, built-in LED lighting that rotates through multiple colors, including blue and orange!

The Tetra ColorFusion LED Aquarium Kit will make your fish tank come alive with color. The LED light cycles through the colors of the rainbow, and you can customize it to your liking. You can pause on any color or turn off the light for a soothing nightlight effect. The anemones sway with your filter current and give your fish a place to hide and relax, while Tetra plants come to life under the glow of Color Fusion LED.

The Tetra ColorFusion Kit includes one 20-Gallon aquarium, a UL heater, and a hood to keep your fish happy. It also comes with one UL Heater, one Tetra Whisper 20 Filter, one Color Fusion Universal Color Changing LED that changes colors when you are all set! This set is perfect for those looking to build a unique seafloor experience or want an elegant display on their desk at work or home.


  • It includes everything required to get started.
  • LED lights with multiple color options.
  • Comes with an instruction guide.
  • Durable and scratch-resistant glass.


  • Glass material is heavy and fragile. 

What To Look For In The Best 20 Gallon Fish Tank

A lot of people are on the hunt for the perfect fish tank. There are so many different sizes, shapes, and designs to choose from! But how do you decide which one is right? 

When purchasing a new 20-gallon fish tank, several factors should be considered. 

Included Accessories

The most essential items for your aquarium setup are – filter, heater, light, and substrate. In addition, you can have decors and live plants in your pet’s home.

The more accessories are included, the better. You won’t have to go out and buy extra parts for your tank or make sure that it is set up just right.

Filtration System

The filtration system of your tank is very important as it helps to keep the water clean. If this isn’t working properly, which can be caused by cheap parts or a poorly made design-then you will have an awful time as unhealthy tanks could potentially kill off any fish living there!

An ideal filtration system should consist of three primary stages – biological, mechanical, and chemical filtration.


The question that can come to everyone’s mind is, “How much do I need to spend?” Well, that depends. You shouldn’t buy an extra expensive one, but don’t compromise quality for the price either!


The design of your fish tank is one aspect that you should consider when purchasing. Whether you want a traditional or modern design, fish tanks come in many different styles, depending on your needs. For instance, if the size is at issue for space limitation, slimline models are available that will still provide adequate volume. 

When it comes to setting up an aquarium, the aesthetics of your fish tank are important. However, make sure not to overlook how easy setup can make!

Material Of Construction

Aquariums have a few different choices when it pertains to the material of construction. The next decision you have to make is how the fish tank will be constructed – glass or acrylic?

I constantly suggest glass because of its sturdy nature and low cost- not only that, but with time your fishies can swim around in crystal clear water! Glass tanks are suitable to utilize with various types of heaters, which is a substantial advantage.

If you’re looking for something with more toughness, Acrylic tanks are also a wonderful selection. They do not break as easily, making them less complicated to maintain cleanliness without fretting damaged fixtures.

4 EASY Tank Setups For A 20-Gallon Aquarium

How Many Fish For A 20-Gallon Tank?

The amount of fish you can maintain depends upon your tank’s dimension and the size of the fish you keep. 

In a simple rule of thumb, you can keep 1 inch of fish per gallon, based upon the size of the fish when they are fully adult. So, you can have 20 fully grown fish that maxes at 1 inch.

You can also read: How Many Fish Per Gallon – The Ultimate Stocking Guide.

When picking fish for your aquarium, make sure all the types have similar water needs so that you can set up the most ideal water environment for them. 

20 Gallon Tank Setup Ideas

This section of the post will give you some idea of how to set up your 20-gallon aquarium and make it look incredible.

Fish-Only Aquarium

20-Gallon Fish-Only Aquarium

Fish-only tanks are a great way to fill your home with the perfect backdrop of aquatic life. For this type of tank, it’s best to use hardscape materials like gravel and rock or wood for decoration to create something natural-looking without having any greenery around!

Planted Aquarium

20-Gallon Planted Aquarium

The natural aquascape is an exciting and creative type of fish tank decoration. This style uses the plants within your aquarium to create a landscape-like scene, where you can place rocks or wood for added effect! Live plants also play an important role in this design; it’s best paired with other greenery that will provide hiding places for animals like crawfish and snails.

Species Tank

20-Gallon Species Tank

Some of the most beautiful and fascinating aquarium creatures are not suitable to keep in community tanks. Although they can be aggressive to other fish or with specific care requirements, such as Puffers (a type of South American livebearer), Dwarf Cichlid; Bettas from Southeast Asia; or some kinds of Gouramis. All these species make great additions to your tank if you want an exciting display! 

A 20-gallon aquarium is also suitable for some specific species that are aggressive to other fish or require particular care requirements. You can keep one or two different types in the same tank if you want!

Shrimp Tank

20-Gallon Shrimp Tank

Shrimp also enjoy hiding places, but they’re a little more adventurous than most. If you have the perfect tank for them with caves or wood that looks like it belongs in an aquarium ecosystem, then this might just be their style! Utilize these manmade cavities as well by making sure there are plenty of natural-looking leaves and branches around to make your shrimp feel at home.

Saltwater Tank With Live Rock (FOWLR)

20-Gallon Saltwater Tank With Live Rock

You can have a marine tank with live rock, and you’ll love the natural-forming caves for your fish. Live rock is a great way to create natural caves and hiding spots for your fish. However, make sure everything is not stacked or put together too tightly as it may be hard to clean up after them!

Aquaponics Fish Tank

20-Gallon Aquaponics Fish Tank

Aquaponic fish tanks are self-sustaining aquariums and already have the natural look of plants growing on top. The 20-gallon kit will allow you to build your own for this type, which is excellent if sustainability or simplicity interests you!

Wrapping Up

So here’s the thing, if you’re looking for an excellent 20-gallon fish tank on the market today, it can be hard to find. You might need some help sorting through all of them out there and figuring out which one is best suited for your needs. Which brings us back to our original question – what is the Best 20 Gallon Fish Tank

I hope this guide has helped and this article has given you enough information to make the best decision! 

If you want to know anything more, please leave a comment below with any questions or concerns so that our team of experts can help answer them.

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